String在swift 4.1中转换为double

Question

let getLongijson: String = "67.0011"
let getlatijson: String = "24.8607"

let jsonlong = (getLongijson as NSString).doubleValue
let jsonlat = (getlatijson as NSString).doubleValue

我遇到这个错误     不能在属性初始值设定项中使用实例成员'getLongijson';属性初始化程序在'self'可用之前运行

Answer 1

您希望将String转换为Double：

let getLongijson: String = "67.0011"
let getlatijson: String = "24.8607"

let jsonlong = Double(getLongijson)
let jsonlat = Double(getlatijson)